GoogleChrome / GoogleChrome/lighthouse

TBT is incorrect for script type="module"

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#14,739 4 comments 0 reactions 1 assignee Assigned to @paulirish View on GitHub
bug P1.5
Dominant language
JavaScript
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Description

### FAQ

- [X] Yes, my issue is not about [variability](https://github.com/GoogleChrome/lighthouse/blob/main/docs/variability.md) or [throttling](https://github.com/GoogleChrome/lighthouse/blob/main/docs/throttling.md).
- [X] Yes, my issue is not about a specific accessibility audit (file with [axe-core](https://github.com/dequelabs/axe-core) instead).

### URL

https://bwin.de

### What happened?

The Total Blocking Time (TBT) is incorrect if the page uses ``.

The value is almost 0:
![Lighthouse](https://user-images.githubusercontent.com/7845502/215726119-0ed96534-02a6-420e-ae72-d06472ef55ad.png)

Because the time of "Evaluate module" is not considered:
![Performance](https://user-images.githubusercontent.com/7845502/215726112-7d592adf-62b3-4b02-974d-5be5a30329db.png)

### What did you expect?

"Evaluate module" should be treated the same way like "Evaluate script".

### What have you tried?

Comparison between Lighthouse Audit and Performance analysis in Chrome Dev Tools.
The page insight test has the same results.

### How were you running Lighthouse?

Chrome DevTools

### Lighthouse Version

9.6.8

### Chrome Version

109.0.5414.119

### Node Version

_No response_

### OS

Mac

### Relevant log output

_No response_

Contributor guide

Open the contributing guide

Assessment

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